Electric heating furnace



May 26, 1964 c. A. MALNowsK 3 3 ELECTRIC HEATING FURNACE Filed July eeo INVENTOR.-

ATTORNEVS.

United States Patent O 3,134,836 ELECTRIC HEATING FURNACE Cheste' A. Malinowski, Chicago, Ill., assignor to Lindberg Engineering Company, Chicago, Ill., a Corporation of Illinos Filed July 11, 1960, Ser. No. 42,153 '2 Claims. (CI. 13-25) This invention relates to electric heating furnaces and more specifically to the Construction and mounting of heating elements for such a furnace.

In electric heating furnaces, ovens and the like, all of which are referred to herein as "furnacesj' there are a number of advantages in the use of stranded heating elements. Such elements have a given size and Capacity, and are easier and less expensive to form and to install than solid elements since lengths of resistance wire of standard diameters can be employed in making up the elements.

The principal problem in connection with the use of stranded heating elements has been the mounting thereof in the furnace. If the strands are pre-forned into a cable or bundle, it becomes difiicult to form to the desired configuration and to handle. On the other hand, if the strands are handled separately, they must be threaded through or individually Secured to supporting insulators or the like and this becomes a dificult and tedious operation.

It is, therefore, one of the objects of the present invention to provide an electric heating furnace in which stranded heating elements are easily mounted in place without the difliculties of handling pre-formed bundles or of threading or otherwise attaching separate strands to supporting insulators.

Another object is to provide an electric heating furnace in which individual strands forming the heating elements are easily passed through gaps in annular supporting insulators and are then Secured into a bundle of larger diameter than the gap to be retained in place in the insulators.

According to a feature of the invention, the supporting insulators are mounted on the furnace wall by non-circular mounting projections thereon extending through corresponding openings in the furnace wall and then turned relative thereto, the bundle of strands passing through the insulators preventing turning thereof back to a position in which the projections can pass through the openings.

The above and other objects and features of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which:

FIGURE 1 is a View partly in section and partly in elevation showing a heating element and a mounting therefor according to the invention;

FIGURE 2 is a top plan view with parts in section similar to FIGURE 1 showing the manner of installing the heating element; and

FIGURE 3 is a partial elevation looking from the right in FIGURE 2.

As shown, electric stranded heating elements indicated generally at and formed of a plurality of separate strands tied together into a generally circular bundle are adapted to be supported in a furnace in spaced relation to the inner wall 11 thereof. The heating elements are supported by insulators indicated generally at 12 formed of suitable non-conducting material such as a refractory or ceramic material and which are mounted on the furnace wall to support the heating elements.

According to one feature of the invention the insulators are mounted on the furnace Wall by providing noncircular mounting projections 13 at one side of the insulators to extend through correspondingly shaped openings 14 formed in the furnace wall. As shown, the mounting projections 13 and the openings 14 are square in Outline although any other preferred non-circular shape could be employed equally well.

F or mounting the insulators they are turned to a position in which the mounting projections 13 register with and can pass through the openings 14 and are then turned through an angle of approximately to move the mounting'projections out of registry With the openings as seen in FIGURE 3. With the insulators turned to the mounted position shown in FIGURE 3, the portions thereof which support the heating elements are aligned properly in their supporting positions so that the heating elements will be supported properly thereby. At the same time the heating elements will engage the insulators and prevent them from turning so that they cannot accidentally turn back to a position in which the mounting projections could pass through the openings in the furnace wall.

The main portons of the insulators, as best seen in FIGURE 2, are generally annular with a relatively narrow gap 15 provided at one point therein. As shown in FIGURE 2, the insulator bodies may be generally square in Outline to provide a square internal opening with the gap 15 opening into one corner of the central opening, although this exact location is not critical.

With the insulators in place in the furnace body, the heating elements may be mounted therein by passing in dividual strands, as shown at 16 in FIGURE 2, through the gap 15 and into the enlarged central opening in the insulator body. After a desired number of strands have been inserted through the gap 15, the strands may be tied together by bindings 17 on opposte sides of the insulators to hold them securely in a bundle.

It will be apparent that the bundle is of substantially greater diameter than the width of the gap 15 so that it is Secured in the insulator and can be held thereby in either a vertical or horizontal position, as desired.

With the heating elements and mountings therefor constructed according to the present invention, the several insulators may be mounted in place and the strands which make up the heating elements can be wound through and around the insulators in any desired pattern in a very simple and easy manner.

Thus, the heating elements could be easily formed of wires of indeterminate length which are passed into the openings in the several insulators in the desired succession until the desired number of strands are in place. The installation is then easily completed by fastening the ties 17 in place to provide an accurate and easily assembled furnace Construction.

While one embodiment of the invention has been shown and described in detail, it will be understood that this is for the purpose of illustration only and is not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. An electric heating furnace comprising a wall defining a portion of a furnace chamber, a heating element supported on the wall in spaced relation thereto formed by a plurality of separate strands, means securing the strands together in a bundle, a plurality of insulators mounted in space relationship on the furnace wall and supporting the heating element in a desired configuration, each of said insulators including a body having a central opening through which said bundle extends, said body having a gap therein of a width to pass a single strand but not to pass the bundle of strands, and the `tion thereon to extend through the opening and be turned relative thereto to mount the insulator, the bundle of strands extending through the insulator preventing it from turning to a position in which the mounting projection can pass through the opening.

References Cited in the file of this patent UNITED STATES PATENTS 966,311 Clark Aug. 2, 1910 Hunter June 4, Cutter Mar. 15, MacInnes Nov. 19, Woodson et al. June 7, Simpson Aug. 22, Techroew Sept. 25, Stevens Dec. 22,

FOREIGN PATENT S Germany J an. 22, Germany June 9, 

1. AN ELECTRIC HEATING FURNACE COMPRISING A WALL DEFINING A PORTION OF A FURNACE CHAMBER, A HEATING ELEMENT SUPPORTED ON THE WALL IN SPACED RELATION THERETO FORMED BY A PLURALITY OF SEPARATE STRANDS, MEANS SECURING THE STRANDS TOGETHER IN A BUNDLE, A PLURALITY OF INSULATORS MOUNTED IN SPACE RELATIONSHIP ON THE FURNACE WALL AND SUPPORTING THE HEATING ELEMENT IN A DESIRED CONFIGURATION, EACH OF SAID INSULATORS INCLUDING A BODY HAVING A CENTRAL OPENING THROUGH WHICH SAID BUNDLE EXTENDS, SAID BODY HAVING A GAP THEREIN OF A WIDTH TO PASS A SINGLE STRAND BUT NOT TO PASS THE BUNDLE OF STRANDS, AND THE SECURING MEANS INCLUDING TIES ADJACENT BOTH SIDES OF EACH OF SAID INSULATORS. 